Roundup of Global Volcanic Activity
Kliuchevskoi (Kamchatka): As had been previously suggested, the volcano’s most recent eruptive phase had become both effusive and explosive: in addition to ash-generating strombolian explosions from the summit vent, a new, but short-lived lava flow appeared during 23 or 24 April and descended approx. 800 m on the south-eastern flank of the volcano (along the Apakhonchich ravine). It seems that the lava flow remained active at least until Tue (26 April) according to KVERT’s daily reports and images from the local observatory, but seems to have stopped by now; glow is no longer visible on clear webcam imagery from yesterday and today. A significant, continuous steam plume suggests that mild explosive activity continues.
Ruapehu (North Island): An earthquake swarm has been occurring at the volcano since 26 April. According to Geonet, such seismic swarms indicating small rock-fracturing events have been rare at the volcano in recent years. Ruapehu’s typical seismic activity is rather dominated by events reflecting internal circulation of fluids such as tremor.
White Island (New Zealand): A small phreatic explosion occurred inside the main crater of the volcano on the evening of 27 April around 21:50 local time, Geonet reported. The volcanic alert level was raised to 3 and aviation color code to Orange. Since the eruption, the volcano has returned to quiet / normal activity and the alert level was again lowered to 2 (although aviation color code remains orange for the time being as other explosions could occur).
Cleveland (Aleutian Islands, Alaska): The Alaska volcano observatory lowered the alert level to yellow, after no more activity has been observed at the volcano since the small explosion on 16 April. “Seismicity returned to low levels within an hour of the explosion, and there have been no infrasound (pressure sensor) signals detected. Recent satellite views indicate that the August 2015 lava dome is gone and has been replaced with a small cinder cone within the summit crater. Based on seismic levels remaining low since the eruption, and no observations or reports of continued eruptive activity, AVO is reducing the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY.”